Losing trans fluid

[ttee]

I have a 1997 dt466 with an automatic Allison 2000 transmission.

When I check the trans fluid it shows pretty low on the dip stick. I add a couple quarts and it reads normal. I'll drive around, park it. Then when I check it before starting it's low again.

There's no leaks on the driveway. No weeping lines.

Anyone had a trans fluid leak with no obvious leak?

[jimmythomas]

How much fluid does the transmission hold ? I think my Allison 3000 holds 5 gallons?
So the low mark on the stick might be a gallon from full.
Make sure you check the fluid in the same level spot.
Good Luck!

[Booyah45828]

Well, for starters, you check the fluid on allisons with the bus running and in neutral. So if you're checking before you start it, that's your issue. Check it with it running.

Second, fluid level can vary on the dipstick based off of temperature. They'll either have 2 crosshatch areas for both cold and hot fluid temps. OR one crosshatch area for hot fluid. If the fluid is cold and not in the crosshatch area, I typically wouldn't worry, so long as the level is on the stick and not in the "add" area.

The only "phantom" place a transmission can leak is through the cooler, but the lost fluid will appear into the coolant. ATF floats on the coolant, especially several quarts, so if the reservoir and radiator aren't overfull and show none, you can rule out the cooler leaking.